Hand-held power tools, such as cordless screw drills or drills, are conventional. To increase the possible applications for a hand-held power tool such as a screwdriver or screw drill, a tool attachment is detachably mounted on the hand-held power tool. Thus, for example, conventional angle attachments have an output shaft that is situated at an angle with respect to the drive shaft of the hand-held power tool. Furthermore, in conventional eccentric attachments, the output shaft is offset in parallel to the drive shaft of the hand-held power tool.
Various types of fastenings are available for detachably mounting a tool attachment on the housing of a hand-held power tool.
German Patent Application No. DE 101 09 956 B4 describes a hand-held power tool including exchangeable tool attachments that are fastened to the tool via a bayonet joint. It is disadvantageous that the bayonet joint cannot be locked, so that it may come loose by itself due to vibrations occurring during operation of the hand-held power tool. This may result in damage to the tool attachment and/or the hand-held power tool, as well as injury to a user of the hand-held power tool. In addition, it has been found disadvantageous that there is no unambiguous, reproducible angular position of the locking element with respect to the tool housing in the locking state of the bayonet joint, so that the locking state cannot be unequivocally indicated.
German Patent Application No. DE 20 2013 102 832 U1 describes an option for locking the connection of a tool attachment to a gear housing of a hand-held power tool; however, the axial locking of the tool attachment is achieved here with the aid of a ball that engages with a circumferential groove in the spindle of the power tool. With respect to the implementation with the aid of a bayonet joint, this in turn has the disadvantage that a large tilting clearance occurs in the interface between the tool attachment and the gear housing, which is undesirable.
German Patent Application No. DE 10 2013 213 804 A1 describes a hand-held power tool that includes a fastening interface, designed as a bayonet joint, for accommodating a tool attachment, it being possible to lock the fastening interface via a blocking element. In this approach as well, it is disadvantageous that there is no unambiguous, reproducible angular position of the locking element with respect to the gear housing, so that the locking state cannot be unequivocally indicated.